The present invention relates to a decorative sheet used as a material for a table cover, a shower curtain, a window decoration sheet, a pouch and the like.
As a decorative substance whose pattern or color is changed depending upon a visual angle or a decorative substance for providing a three-dimensional effect to a plane sheet, a lenticular plate including semicylindrical lenses, namely, convex lenses each having an arch section, is conventionally used.
When a decorative substance like, for example, a post card is produced by using a lenticular plate, it is necessary to make a pitch of a printed material accurately accord with a pitch of the lenticular plate. Therefore, there are problems of very high accuracy required in the production, a high cost and a large percent of defectives.
Also, in general, in order to attain a 3-D (three-dimensional) effect, a three-dimensional image is photographically formed. Therefore, the usage of a lenticular plate is occasionally poor in generality, and merely a comparatively small product can be obtained by using a lenticular plate. Also, photographic paper or the like is necessary for placing a lenticular plate on material paper, and hence, the product is lack of flexibility. Moreover, since a lenticular plate has a structure in which above-mentioned semicylindrical lenses are repeatedly formed, when a soft material is used, a valley portion between the semicylindrical lenses can become a slit line and the product can be easily torn.